Trifluridine (another name: α,α,α-trifluorothymidine; hereinafter also called “FTD”) interferes with DNA synthesis by inhibition of thymidylate synthesis and interferes with DNA function by incorporation into DNA, thus exerting anti-tumor effects. Meanwhile, tipiracil hydrochloride (chemical name: 5-chloro-6-[(2-iminopyrrolidin-1-yl) methyl]pyrimidine-2,4(1H,3H)-dione hydrochloride; hereinafter also called “TPI”) has a thymidine phosphorylase inhibitory effect. It is known that TPI suppresses in vivo degradation of FTD by thymidine phosphorylase, thus enhancing the anti-tumor effect of FTD (Patent Literature 1). At the present time, an anti-tumor agent comprising FTD and TPI at a molar ratio of 1:0.5 (hereinafter also called “FTD⋅TPI combination drug”) has been developed as a therapeutic agent of solid cancers and is approved in Japan as a therapeutic agent for advanced or recurrent colorectal cancer (Non-Patent Literature 1 and 2).
In order to enhance the anti-tumor effect of the FTD⋅TPI combination drug, combination therapies have been studied, and the studies have suggested combination effects of the combination drug or FTD with irinotecan, oxaliplatin, docetaxel, or the like (Non-Patent Literature 3 to 5).
Anti-tumor platinum complexes are metal complex compounds containing platinum as the central metal, and inhibit DNA replication by binding to DNA, thus exerting anti-tumor effects. Platinum complexes as anti-tumor agents have been studied for a long time, and cisplatin, carboplatin, oxaliplatin, and the like are clinically used against a wide variety of cancer types (Non-Patent Literature 6). Combination use of anti-tumor platinum complexes with various anti-tumor agents has also been studied. In particular, combination use with an antimetabolite such as 5-fluorouracil is widely adopted.